Method and apparatus for providing a low-latency connection between a data processor and a remote graphical user interface over a network

Abstract

A pair of processing modules and methods that enable low latency communications between a data processing system and devices located at a remote graphic user interface across a standard shared network in accordance with the present invention is disclosed. The present invention provides a method for communicating graphics data in a synchronous manner from the data processing system to the user. This method is used in conjunction with a feedback error recovery method to provide lossless, low-latency communications of graphics data across the network.

1. A method of displaying low-latency raster scan images, comprising:
 receiving, at a client computer, a display scan line of a remote host computer, the receiving via an IP/Ethernet network, the display scan line associated with a position of a raster scan signal produced by the remote host computer; 
 identifying a latency between the receiving a display scan line and a displaying of the display scan line; 
 adjusting an operating frequency of the client computer based on the latency; and 
 displaying the display scan line at the operating frequency of the client computer. 
 
     
     
       2. The method of  claim 1 , wherein the latency comprises an anticipated latency between the receiving a display scan line and a scheduled displaying of the display scan line. 
     
     
       3. The method of  claim 1 , wherein the identifying a latency comprises determining a scan line count. 
     
     
       4. The method of  claim 1  further comprising:
 communicating, between the client computer and the remote host computer, via the IP/Ethernet network, computer raster scan parameters; and 
 setting configurable parameters of the client computer based on the computer raster scan parameters, the configurable parameters comprising an initial value of the operating frequency of the client computer, wherein an initial display scan line is displayed in accordance with a defined initial value of a scan line delay. 
 
     
     
       5. The method of  claim 4  wherein the computer raster scan parameters comprise a display requirement of the remote host computer and a display capability of the client computer and the setting configurable parameters comprises setting a display size required by the remote host computer and capable of the client computer. 
     
     
       6. The method of  claim 4 , wherein the scan line delay is correlated to characteristics of the IP/Ethernet network. 
     
     
       7. The method of  claim 6 , wherein the characteristics of the IP/Ethernet network comprise a relative delay histogram identifying a relationship of packet latency to arrival probability. 
     
     
       8. The method of  claim 4 , wherein the scan line delay comprises a delay of less than one image frame. 
     
     
       9. The method of  claim 4  wherein the adjusting an operating frequency is performed such that the operating frequency is maintained within a controllable range, the controllable range based on the computer raster scan parameters. 
     
     
       10. The method of  claim 1 , wherein the adjusting an operating frequency comprises adjusting a balance between causal delay and a packet loss indicia. 
     
     
       11. Apparatus for displaying low-latency raster scan images, comprising:
 a network controller enabled to receive a plurality of encoded scan lines via a computer network, the plurality of encoded scan lines comprising a plurality of raster scan lines generated at a remote host computer; 
 a decoder, coupled to the network controller, enabled to decode each of the plurality of encoded scan lines to generate a plurality of decoded scan lines; 
 a transmitter, coupled to the decoder, enabled to transmit a client raster signal comprising the plurality of decoded scan lines, wherein an operating frequency for the transmitter is adjusted based on a latency between receiving a selection of the plurality of encoded scan lines and transmitting a decoding of the selection; and 
 a remote display controller, the remote display controller enabled to communicate with the remote host computer capabilities of a display device coupled to the transmitter. 
 
     
     
       12. The apparatus of  claim 11 , wherein the transmitter comprises a display controller, the display controller comprising a display clock and the display clock comprising the operating frequency. 
     
     
       13. The apparatus of  claim 11 , wherein the latency comprises a delay between receiving at least one of the selection and transmitting a decoding of the at least one of the selection. 
     
     
       14. The apparatus of  claim 11 , wherein the latency is determined by a scan line counter, the scan line counter identifying a delay between receiving at least one of the plurality of encoded scan lines and transmitting at least one of the plurality of decoded scan lines, the at least one of the plurality of decoded scan lines decoded from the at least one of the plurality of encoded scan lines. 
     
     
       15. The apparatus of  claim 11 , wherein the client raster signal is synchronized and equivalent to a host raster signal comprising the plurality of raster scan lines.